Method and apparatus for creating channels through vascular total occlusions

• US 6,416,523 B1
• Filed: 10/03/2000
• Issued: 07/09/2002
• Est. Priority Date: 10/03/2000
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Lafontaine, Daniel M.
• Primary Examiner(s): Schaetzle, Kennedy
• Assistant Examiner(s): DROESCH, KRISTEN L
• Application Number:
  US09/678,147
• Time in Patent Office: 644 Days
• Field of Search: 606/159, 606/170, 606/171, 604/22, 607/9, 607/11, 607/28, 600/373, 600/547
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320758 with a rotating cutting instrument, e.g. motor driven A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002
• CPC Class Codes: A61B 17/3474 Insufflating needles, e.g. Veress needles
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/0003 of parts of the instruments
• CPC Class Codes: A61B 2017/22067 Blocking; Occlusion A61B2017/22054 takes precedence
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2017/22082 after introduction of a substance
• CPC Class Codes: A61B 2017/22094 for crossing total occlusions, i.e. piercing
• CPC Class Codes: A61B 2090/08021 of the patient or his organs
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61B 2217/007 with irrigation system

Abstract

A method and apparatus for creating a lumen through a total vascular occlusion. A directional cutter is advanced ahead of a number of proximal electrodes that engage a vessel wall. Blood in the vessel between the directional cutter and the proximal electrodes is removed by sealing the vessel with an occluding balloon and pumping a bio-compatible gas into the vessel to displace the blood. A signal source is applied to the directional cutter and used to measure the impedance between the directional cutter and each of the proximal electrodes. If the cutter engages a vessel wall, the impedance between the cutter and the proximal electrode decreases. A physician monitors the impedance to know when the vessel wall is engaged and turns the direction of the cutter away from the vessel wall such that the cutter continues creating a lumen within the occluding material. Once a lumen has been created in the occluding material, the cutter and electrodes are removed from the vessel and the vessel is treated with a conventional atherectomy device. In another embodiment of the invention, the signal source supplies a pacing signal to the directional cutter. If the cutter is embedded within an occlusion, the heart is not captured by the pacing signal. Once the cutter contact the vessel wall, the heart is captured and the physician changes the direction of the cutter to continue creating the lumen within the occlusion.

Claims

1. A system for creating a lumen through a total vascular occlusion, comprising:

a directional cutter that directionally creates a lumen within an occlusion;

a plurality of isolated electrodes that are adapted to contact a vessel wall proximal to the cutter;

a signal source for supplying current between the cutter and the plurality of electrodes; and

a circuit for measuring an impedance between the cutter and the plurality of electrodes, wherein the impedance varies when the cutter is in the occlusion versus when the cutter is in contact with the vessel wall such that the direction of the cutter can be changed to advance the cutter through the total vascular occlusion.

2. The system of claim 1, further comprising:

a catheter through which the cutter and plurality of electrodes are routed, the catheter including a sealing mechanism for selectively occluding the vessel proximal to the cutter.

3. The system of claim 1, further comprising:

a lumen for delivering a bio-compatible gas to the vessel to displace blood between the cutter and the plurality of electrodes.

4. The system of claim 1, further comprising:

one or more switches that selectively couple the signal source and impedance measuring circuit between the cutter and each of the plurality of electrodes sequentially, in order to detect the impedance between the cutter and each of the plurality of electrodes.

5. The system of claim 1, further comprising a display that visually indicates the relative impedance between the cutter and each of the plurality of electrodes.

6. The system of claim 1, wherein the plurality of electrodes are formed as an expanding stent.

7. A system for creating a lumen through a total vascular occlusion, comprising:

a directional cutter that creates a lumen within the occlusion;

a plurality of isolated electrodes that are adapted to contact a vessel wall;

a signal source for supplying an electrical signal between the cutter and the plurality of electrodes; and

a circuit for measuring an impedance between the cutter and the plurality of electrodes in order to determine when the cutter engages the vessel wall so that the direction of the cutter can be changed to advance through the occlusion.

8. A system for creating a lumen through a total occlusion, comprising:

a directional cutter that creates a lumen within the total occlusion;

a plurality of isolated electrodes at least some of which are adapted to contact a vessel wall proximal to the cutter;

a signal source that supplies an electrical signal between the directional cutter and the plurality of isolated electrodes;

a circuit for indicating a relative impedance between the cutter and the plurality of isolated electrodes, wherein said impedance drops between the cutter and an isolated electrode that is nearest said cutter when said cutter engages a vessel wall, said directional cutter being turned away from said nearest isolated electrode after the cutter engages a vessel wall to continue cutting through said total occlusion.

9. A system for creating a lumen through a total vascular occlusion, comprising:

a cutter that creates a lumen within an occlusion;

a plurality of isolated electrodes formed as an expanding stent that are adapted to contact a vessel wall proximal to the cutter;

a signal source for supplying current between the cutter and the plurality of electrodes; and

a circuit for measuring an impedance between the cutter and the plurality of electrodes, wherein the impedance varies when the cutter is in the occlusion versus when the cutter is in contact with the vessel wall.

10. A method of creating a lumen within a total vascular occlusion, comprising:

advancing a cutter into the occlusion;

placing a plurality of electrodes proximal to the cutter;

displacing blood in the vessel between the cutter and the plurality of electrodes;

measuring the impedance between the cutter and the plurality of electrodes; and

changing the direction of the cutter within the occlusion when the impedance indicates the cutter has engaged the vessel wall.

11. A system for creating a lumen through a total vascular occlusion, comprising:

a cutter that creates a lumen within an occlusion;

a signal source coupled to the cutter for applying a pacing signal to the cutter, wherein said lumen pacing signal causes a change in a heart rate of a patient when the cutter engages a vessel wall and does not change the heart rate when the cutter is embedded in the occlusion; and

a heart rate detector that monitors a change in heart rate such that a physician can change the direction of the cutter in a vessel upon detection of the cutter engaging the vessel wall.